This is an evolution over the earlier R.O.B.B.I. v1.0 platform. It is a biped wall follower that can find its way through a maze by just following the right wall. It is built using RIS 2.0 parts plus an extra aftermarket sensor.

How it works:

The dual infrared proximity sensor DIRPD-T from Technostuff is mounted vertically on the right leg of the biped. It can determine whether the robot is walking parallel to the right wall and identify any openings.
The Lego Light Sensor (included in the RIS 2.0 kit) is also mounted vertically in the front of the robot facing downwards. The exit of the maze is marked as a black patch of ground (The 3.5 floppy disk in the image below). The Light Sensor halts the robot as soon as it is over a black patch making a beeping sound from the internal speaker.
Finally a bumper (based on the Constructopedia instructions) is mounted in front of the robot. The two vertical "straws" protruding are used to detect lower obstacles. The bumper "feels" obstacles ahead and makes the robot walk backwards and avoid them.

Programming:
The robot is programmed in C using the BrickOS kernel for the RCX. The programming architecture is concurrent. There are 3 seperate threads:

* detect_wall
* detect_light
* detect_object

that run simultaneously summing up to the wall following behaviour of the biped. Source code can be found here.

Limitations

The project is still in development. Due to the unstable nature of the biped, sometimes it can collapse when hitting a wall. Also, since the robot tilts in order to move forward, it sometimes bang itself on the "walls" of the maze forcing it out of its straight path. Using a wheel rover for such application would be easier but instead we can understand the limitations imposed by the biped architecture.

Here are some videos that show "Mammoth" in action. More to follow soon.

Divx Videos - No MusicDivx Codec needed. If you don't have it you can download it from here.